Air tightness test and stoves

B

BMD

Registered User
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133
Hi,

Does anyone know the correct procedure for carrying out an air-tightness test in a house that has stoves installed? It is clear that chimney's should be blocked in the case of open fires however what is recommended for stoves?

In the case of stoves with external air supplies, should the air inlet pipe into the stove be sealed or left open?

In the case where chimney's are blocked, I assume this should be done from below as opposed to at the top of the chimney?

Finally, should kitchen extract vents be sealed or left open?
 
This post from 2008 on AAM seems very relevant to the discussion.
The following thoughts spring to mind when you consider the intent of sealing.

- What relevance would the results of an air-tightness test have, if you taped up your vents before the test?
- Unless they are going to be blocked when you use the house you will get a distorted picture of the efficiency of the house.
- If you have uncontrolled admission of air without a heat exchange operation you will affect both your BER rating and air-tightness.

I am not an expert on this BMD, and I have read some discussions on the subject when seemed to be by knowledgeable people but made no sense to me.
Other people have posted comments recently on this and perhaps Low CO2 Design might comment as I understand he has some expertise with Passive Haus design.
My view - and I accept others may have a different view, - is that if you want to seal your house to improve thermal efficiency you need an MVHR system and no vents.


ONQ.

[broken link removed]

All advice on AAM is remote from the situation and cannot be relied upon as a defence or support - in and of itself - should legal action be taken.
Competent legal and building professionals should be asked to advise in Real Life with rights to inspect and issue reports on the matter at hand.
 
BMD said:
Hi,

Does anyone know the correct procedure for carrying out an air-tightness test in a house that has stoves installed?
Click to expand...
sealed temporarily
BMD said:
In the case where chimney's are blocked, I assume this should be done from below as opposed to at the top of the chimney?
Click to expand...
either-or, it depends on future plans...
BMD said:
Finally, should kitchen extract vents be sealed or left open?
Click to expand...
sealed temporarily

I notice this is not the only forum you have posted the same question on! but regardless why are you not asking your air-tightness tester?
 
onq said:
My view - and I accept others may have a different view, - is that if you want to seal your house to improve thermal efficiency you need an MVHR system and no vents.
Click to expand...
yep thats the passive house idea, MVHR or the highway.. preferfectly acceptable option if its a new build or a 'deep retro-fit'. there are studies as far back as the 80's, reckon its the best balance, for conserving energy..

Recently I've been considering DCMEV for retro-fitting.. its something seamus (Viking.H) and J. Little have written about. i like the idea of maybe preheating the air through a conservatory or some variation. there does seem to be some merit to it given how difficult it can be to retro-fit air-tightness and the main question many people ask 'why do i need wall vents when my house is full of drafts?'
 
Hi LCO2D,

Thanks for commenting on this

What is DCMEV?

ONQ.

[broken link removed]

All advice on AAM is remote from the situation and cannot be relied upon as a defence or support - in and of itself - should legal action be taken.
Competent legal and building professionals should be asked to advise in Real Life with rights to inspect and issue reports on the matter at hand.
 
lowCO2design said:
sealed temporarily
either-or, it depends on future plans...

sealed temporarily

I notice this is not the only forum you have posted the same question on! but regardless why are you not asking your air-tightness tester?
Click to expand...


Intending no disrespect, this sounds like a fudge to me.
How is the air-tightness test relevant to the normal use of the building?


ONQ.

[broken link removed]

All advice on AAM is remote from the situation and cannot be relied upon as a defence or support - in and of itself - should legal action be taken.
Competent legal and building professionals should be asked to advise in Real Life with rights to inspect and issue reports on the matter at hand.
 
can you elaborate I'm not sure what you mean? 'relevant to the normal use of the building'. I was under the impression Air-testing/tightness is a requirement..
 
onq said:
What is DCMEV?
Click to expand...
demand controlled mechanical extract ventilation. ie 1 step on from WC & kitchen extract vents, only incorporating RH and CO2 sensors so the standard wall vents are closed till fresh air is required.
there is an argument re smaller primary energy demand + lower install/ less disruption/ cost V heat recovery + install/ maintenance/ cost (referring to retro-fit only)
 
lowCO2design said:
can you elaborate I'm not sure what you mean? 'relevant to the normal use of the building'. I was under the impression Air-testing/tightness is a requirement..
Click to expand...


I mean that blocking the vents gives an artificial result for air tightness.
It s seems like testing a ship for sea-worthiness with all holes plugged, them taking them out before going to sea


ONQ.

[broken link removed]

All advice on AAM is remote from the situation and cannot be relied upon as a defence or support - in and of itself - should legal action be taken.
Competent legal and building professionals should be asked to advise in Real Life with rights to inspect and issue reports on the matter at hand.
 

Thanks LCO2D - I've heard of this, just not familiar with the acromym.

It seems an interesting possibility where you have existing vents in the house.
But this is the nub if the matter - this admits cold damp air into the building in an Irish winter.

You may get a lower Co2 footprint than the pseudo-aircon of an MVHR.
Its trading lower operation costs (not much lower I would have thought) for very cold supply air quality.

It seems it basically lets the air get stale until the sensor goes off then opens a hole in the wall to vent the room direct to air.
What's that supposed to be like on a cold damp October day like today - sudden draughts blowing through the house at random intervals?


ONQ.

[broken link removed]

All advice on AAM is remote from the situation and cannot be relied upon as a defence or support - in and of itself - should legal action be taken.
Competent legal and building professionals should be asked to advise in Real Life with rights to inspect and issue reports on the matter at hand.
 
I'm not saying its prefect, (the term 'drafts' makes me think of to air-leakage not ventilation) yes it does admit cold air but, should in theory allow less than permanent wall vents.
 
onq said:
I mean that blocking the vents gives an artificial result for air tightness.
It s seems like testing a ship for sea-worthiness with all holes plugged, them taking them out before going to sea


ONQ.
Click to expand...
yes I see where your come from now.
ventilation good/ necessary/ required by Breg's : air-leakage bad/ drafts/ now finally getting tighter in Bregs

air-tightness is about the latter
 
(nods)

That's the point.
MVHR operates a heat exchange system AND ventilates.

Demand driven ventilation ventilates cold air at odd times.
BTW most permavents admit very little drafts - people tend to block them!


ONQ.

[broken link removed]

All advice on AAM is remote from the situation and cannot be relied upon as a defence or support - in and of itself - should legal action be taken.
Competent legal and building professionals should be asked to advise in Real Life with rights to inspect and issue reports on the matter at hand.
 
ONQ,

I completely agree, I don't understand why you would seal vents when they are usually left open in the normal running of the house but that seems to be the procedure.

I can't find any conclusive information on how stoves should be treated with respect to air-tightness testing. From what I can tell, the air inlets should be blocked (which doesn't make sense to me) while the chimney should be unblocked (which does make sense).

If the stove is fitted correctly surely it won't impact on the air tightness of the house and hence nothing should be sealed.

I have MHRV installed and again that test criteria state that these should be sealed???
 
Perhaps someone can point me towards and air tightness test protocol that states that the inlet air for stoves must be sealed?

Any protocols I have read only deal with open fireplaces (and state that the chimney should be blocked)
 
I'm a bit lost with all this fudging - perhaps LCo2D might oblige


ONQ.

[broken link removed]

All advice on AAM is remote from the situation and cannot be relied upon as a defence or support - in and of itself - should legal action be taken.
Competent legal and building professionals should be asked to advise in Real Life with rights to inspect and issue reports on the matter at hand.
 
lads I fail to see the question here..

bmd, you have a stove (the air-supply is 'only' for the stove) and MVHR (both required to be temporarily sealed during testing) because:
the heating source (& imo this includes the required internal air-supply) and the ventilation/recycled heat source, are both outside of the remit of air-tightness testing and managed separately under the regs, so both are discounted from a test designed to assess air-leakage.

I don't have an air-tightness manual, your assessor will. I would recommend this guy (no connection) [broken link removed]

if you look through his references, you will get more info on the subject
 
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Low C02,

I could argue whether the rationale for the testing design is correct, however I accept your point that the regulations state that air inlet vent should be sealed. A deviation to the test will have to be performed to assess whether the air inlet is well sealed.

Given that the chimney is integral to the building, am I right to assume that it should not be sealed when a stove is fitted? This is what my tester told me but I just want to confirm
 
stove is sealed to the chimney flue? so I don't see the issue, But finally we have gotten to the bottom of this - if you don't trust your tester, get a second opinion (from another tester, not from me) best of luck with, comeback and tell us how you go
 
I'm afraid you are wrong with your conclusion, however thank you for your input. After reading further articles I am satisfied that the recommended procedure is as follows;

In the case of stoves, seal the air inlet but not the chimney.

I don't agree with the science behind this approach but that's for another day.
 
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